Method and apparatus for transferring bulk material between zones at different respective pressures



3,351,390 ERIAL RES Nov. 7, 196 F. DELLSPERGER METHOD AND APPARATUS FOR TRANSFERRING BULK MAT BETWEEN ZONES AT DIFFERENT RESPECTIVE PRESSU Filed March 24, 1965 ll Sheets-Sheet 1 ill M m/Ew Nov. 7, 1967 F. DELLSPERGER 3,351,390

METHOD AND APPARATUS FOR TRANSFERRING BULK MATERIAL BETWEEN ZONES AT DIFFERENT RESPECTIVE PRESSURES Filed March 24, 1965 ll Sheets-Sheet 2 lNVENTOR FRITZ DELLSPERGER g7 WMMW Nov. 7, 1967 F. DELLSPERGER 3,351,390

' METHOD AND APPARATUS FOR TRANSFERRING BULK MATERIAL BETWEEN ZONES AT DIFFERENT RESPECTIVE PRESSURES Filed March 24, 1965 ll Sheets-Sheet 3 INVENTOR mm DELLSPERGER Nov. 7, 1967 F. DELLSPERGER 3,351,390

METHOD AND APPARATUS FOR TRANSFERRING BULK MATERIAL BETWEEN ZONES AT DIFFERENT RESPECTIVE PRESSURES Filed March 24, 1965 ll Sheets-Sheet 4 INVENTOR FR ITZ DELLSPERGEK Nov. 7, 1967 F. DELLSPERGER 3,351,390

METHOD AND APPARATUS FOR TRANSFERRING BULK MATERIAL BETWEEN ZONES AT DIFFERENT RESPECTIVE PRESSURES Filed March 24, 1965 ll Sheets-Sheet 5 INVENTUR FRITZ DELLSPERGER Wm M W Nov. 7, 1967 F. DELLSPERGER 3,351,399

METHOD AND APPARATUS FOR TRANSFERRING BULK MATERIAL BETWEEN ZONES AT DIFFERENT RESPECTIVE PRESSURES Filed March 24, 1965 11 Sheets-Sheet 6 INVENTUR FRITZ DELLSPL'RGER 46v WW6 [MA v Nov. 7, 1967 F. DELLSPERGER 3,351,390 ERIAL METHOD AND APPARATUS FOR TRANSFERRING BULK MAT BETWEEN ZONES AT DIFFERENT RESPECTIVE PREssUREs 1965 11 Sheets-Sheet 7 Filed March 24,

INVEN'TOR FRITZ DELLSPERGER B AWfi/(Alw a/WoL ZM Nov. 7, 1967 F. DELLSPERGER METHOD AND APPARATUS FOR TRANSFERRING BULK MATERIAL BETWEEN ZONES AT DIFFERENT RESPECTIVE PRESSURES Filed March 24, 1965 l1 SheetsSheet 8 Fig. 9

% INVENTOR FRITZ DELL5PER6ER WW 0M0 W Nov. 7, 1967 F. DELLSPERGER 3,351,390

METHOD AND APPARATUS FOR TRANSFERRING BULK MATERIAL BETWEEN ZONES AT DIFFERENT RESPECTIVE PRESSURES Filed March 24, 1965 ll Sheets-Sheet 9 fig. f0

NVEN R FRITZ DELL SPERGER MWOW W Nov. 7, 1967 F. DELLSPERGER METHOD AND APPARATUS FOR TRANSFERRING BULK MAT BETWEEN ZONES AT DIFFERENT RESPECTIVE PRESSURES Filed March 24, 1965 INVENTOR FR ITZ DELL SPERGER Nov. 7, 1967 F. DELLSPERGER 3,351,390

METHOD AND APPARATUS FOR TRANSFERRING BULK MATERIAL BETWEEN ZONES AT DIFFERENT RESPECTIVE PRESSURES Filed March 24, 1965 ll Sheets-Sheet 11 INVENTOR' FR ITZ BELLS PER ER ma/MW United States Patent 3,351,390 METHOD AND APPARATUS FOR TRANSFERRING BULK MATERIAL BETWEEN ZONES AT DIF- FERENT RESPECTIVE PRESSURES Fritz Dellsperger, Niederuzwil, Switzerland, assignor to Gebruder Buhler, Uzwil, Switzerland Filed Mar. 24, 1965, Ser. No. 442,401 Claims priority, application Switzerland, Apr. 1, I964, 4,140/64 25 Claims. (1. 302-49) This invention relates to the transfer of bulk material between zones at different pressures and, more particularly, to a novel method of effecting such transfer and to a novel sluice or look including an upright drum subdivided into sluice chambers each having a respective feed aperture at its upper end and a respective discharge aperture at its lower end, with each aperture having a respective closure, and including means for controlling the opening and closing movements of these closures as a function of the relative angular relation of the sluice or lock chambers to a feed device extending into a feed zone in the upper end of the drum.

Sluices or looks with revolving chambers and stationary filling apertures, for the feeding of compressed air conveyors, are known. The known devices have the disadvantage that the closures are stationary relative to the revolving chambers, so that the sealing means disposed between the closures and the chambers are subjected to very heavy stresses due to the relative sliding movement. This is very disadvantageous, particularly in the case of abrasive materials, because of the heavy wear of the contacting surfaces. Moreover, since, in the region of the filling aperture, either the seal is moved toward and away from the contact surface or the surface portion of the chamber defining the opening slides toward and away from the seal, there is very great danger that material becomes wedged between the contact surface and the seal.

Rotating centrifugal chamber type sluices or looks are known, and have flaps or closures opening only under a certain pressure. These aliord a means of avoiding the aforementioned disadvantage but, in turn, have the disadvantages that only bulk material not having a tendency to segregate during spinning can be sluiced therewith. Furthermore, there is the danger that, during the spinning, the material is exposed to unduly high impact stresses.

It is also known to provide sluices or locks which include revolving chambers, a stationary cover with filling apertures opposite these chambers, and individual outlet flaps or covers respective to each chamber and operated by levers and earns. However, sluices or locks of this type present, in the region of the covers, the abovementioned disadvantages of sliding seals and, in the region of the outlet flaps, the disadvantage of very high forces acting on the levers and earns, particularly in the case of relatively large outputs.

An object of the present invention is to provide a method of transferring bulk material between zones .of different pressures and obviating the aforementioned disadvantages.

Another object of the invention is to provide a sluice or lock for transferring bulk material between zones at 7 respective feed and discharge apertures each of which has a respective closure or flap associated therewith and which is movable toward and away from the associated apertures without relative sliding. Furthermore, the means for controlling the opening and closing movements of the closures are individual to each closure and rotate, relative to the feed device, in the same manner as the drum and the feed device rotate relative to each other.

An advantage of the present methods and apparatus is that the pressure differences, already existing during the sluicing of bulk material between zones at different pressures, are used for actuating the means for closing the various closures. At the same time, pressure compensation is effected before opening of the chambers for discharge of material therefrom.

A further object of the invention is to provide a sluice or lock for transferring bulk material and in which various kinds of actuating elements and control elements may be used.

Yet another object of the invention is to provide a sluice or lock for transfer of bulk material between zones at different pressures in which special pressure means are used for actuating the elements of the device and wherein sluicing is possible under pressure conditions.

Yet another object of the invention is to provide a sluice or lock for transfering bulk material between zones at different pressures and comprising a drum rotating relatively to a feed device and subdivided into sluicing chambers, resulting in simpler bearings and smaller driving requirements due to the smaller masses to be moved.

Still another object of the invention is to provide a sluice or lock for transferring bulk material between zones at different pressures including a feed device which rotates relative to a drum, thereby simplifying the driving means.

For an understanding of the inventive principles, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is an elevation view of one form of sluice embodying the invention, together with feed means and delivery means;

FIG. 2 is a side elevation view, partly in section, of a sluice of the type shown in FIG. 1;

FIG. 3 is a sectional view taken on the line IIIIII of FIG. 2;

FIG. 4 is a horizontal sectional view taken on the line IVIV of FIG. 3;

FIG. 5 is a partial sectional view illustrating a detail V of FIG. 3 to an enlarged scale;

FIG. 6 is a partial vertical sectional view of another form of sluice or lock embodying the invention;

FIG. 7 is a vertical sectional view through a further form of sluice or lock embodying the invention, and taken along the line VII-VII of FIG. 8;

FIG. 8 is a horizontal sectional view taken on the line VIIIVIII of FIG. 7;

FIGS. 9, 10 and 11 are vertical sectional views through further sluices or locks embodying the invention, with FIG. 11 being taken on the line XI-XI of FIG. 8; and

FIG. 12 is an elevation view of the sluice or lock shown in FIG. 11 in association with a dust separator and dust sluice, the latter being shown in section.

Referring first to the embodiment of the invention shown in FIGS. 1-5, a pneumatic conveyor line 1 opens into a separator 3 which, in turn, is connected through an air aspiration line 4 with a suction blower 5. The discharge of separator 3 is formed by a stationary line which extends, as a feed device 6, through a stationary connection piece 7 and into a rotating drum 10. A motor 12 drives drum through a chain '13, and drum 10 is guided by connecting piece 7 and is supported by a shaft in a bearing 14. A discharge funnel 16 is disposed eccentrically underdrum 10, and arranged over a conveyor belt 17.

Drum 10 is subdivided into four sluice or lock chambers 20 and is extended beyond these chambers into the region of feed device 6 to form a feed separated zone 22 from sluice or lock chambers 20' by a partition 23. Stationary feed device 6 extends into feed zone 22 and terminates in a laterally arranged mouth or discharge opening 25.

Each sluice or lock chamber 20 is provided with an upper feed aperture 26 and a lower discharge aperture 27. Each feed aperture 26 is provided with a respective closure, such as a flap or cover 28, and each discharge aperture 27 is provided with a respective closure, such as a flap or cover 29, these flaps or covers serving as means for closing and essentially sealing the associated chamber. Pneumatically loadable .pistons 32 are connected through longitudinally arcuate rods with upper flaps 28 and are movable, with a certain amount of play, in longitudinally arcuate cylinders 33 extending outwardly from chambers 20. Upper flaps 28 are articulated to levers 35 which, in turn, are swingably mounted in brackets 36. On its surface portions defining the feed apertures, partition 23 is provided with packings 34 facing sluice chambers 20.

When pistons 32 are displaced outwardly of the respective cylinders 33, they clear compensating bores 38 in cylinder 33 establishing communication between sluice chambers 20 and the zones surrounding these sluice chambers. The opposite ends of cylinders 33 are selectively clo'sable by means of control flap valves 40. To actuate flap valves 40, cranks 41 are provided, each having a roll 42 at its free end engageable, in a manner to be described, with a control cam 44. The upper chamber closing means, together with the control devices and the actuating elements therefor, 3042, are mounted on removable covers 45. In the area of feed zone 22, drum 10 is provided with an inspection door 46.

Partition 23 is formed with openings 54 in which there are pressure compensating valves 48 controlled by a cam plate 50 mounted on a fixed shaft 49. Counter weights 51 are provided to close valves 48, these counter weights being on the ends of levers 52, pivoted on brackets 53 and connected with valves 48. Roof-like profiles 55 are arranged between feed apertures 26. The lower flaps, each individual to a respective discharge 27, are operated, relatively synchronously with feed device 6 by a cam 57 engageable with rolls 58 'each secured to a lever 56. By means of springs 60, flaps 29 are biased, relative to levers 56, into closing relation with the respective discharge apertures 27. Levers 56 are pivoted on brackets 61, and packings 62 are provided between each flap 29 and the contact surface bounding its associated discharged aperture 27.

As best seen in FIG. 5, drum 10 is rotatably guided on connecting piece 7 by means of radial thrust rollers 64 and axial thrust balls 65. A packing 66 is disposed between a flange of connecting plate 7 and the toothed rim 68 of drum 10. g

In the operation of the described apparatus, material is drawn through conveyor line 1 into separator 3. While the separated air is drawn off by suction blower 5, the material falls into feed device 6. From feed device 6, the material falls through mouth 25 of the latter and, guided by profiles 55, enters the particular sluice chamber 20 to be filled, and which is located beneath mouth 25 as shown in FIG. 3. At this time, the respective upper flap 28 is opened and the respective lower flap 29 is closed. Feed zone 22 and the sluice chamber 20 to be filled are thus subjected to the negative pressure produced by suction blower 5. A sluice chamber 20 is fed material through mouth 25 of feed device 6 while drum 10 continues to rotate.

with control cam 44. The ambient atmospheric pressure surrounding drum 10 now forces piston 32 downwardly and thus closes upper flap 28. With flap 28 closed, piston 32 clears compensating bores 38, so that sluice chamber 20 is thus subjected to the ambient atmospheric pressure.

After drum 20 has rotated far enough that cam follower 58 disengages cam 57, lower flap 29 opens under the force of its dead weight and the weight of the material lying thereon. The material falls through discharge funnel 16 onto conveyor belt 17 and is conveyed away. Upon further rotation of drum 10, cam follower 58 again engages cam 57 and thus lower flap 29 is re-closed. Then control cam 44 reengages and lifts the associated roller 42 back to its original level thereby to close flap valve 40. Through the medium of cam plate 50, pressure compensating valve 48 is then opened and, through the associated aperture 54, there is effected an evacuation of sluice chamber 20 which, until opening of its compensating valve 48, was under normal or atmospheric pressure. Due to such evacuation, the chamber is now subjected to the negative pressure prevailing in feed zone 22. The upper flap 28 is opened as cam plate 50 releases pressure compensating valve 48 to allow the latter to close, but only after attainment of substantial pressure equilibrium between a sluice chamber 20 and feed zone 22. Simultaneously with the reduction of pressure of the sluice chamber 20, there occurs also a reduction of the pressure in the associated cylinder 35 through the medium of the bores 38 of the latter.

The cycle of operation may be summarized as follows: 1) filling of the sluice or lock chamber and closing of the upper flap by external pressure. (2) external pressure compensation of the sluice or lock chamber and opening of the lower flap. (3) emptying of the sluice or lock chamber and closing of the lower flap. (4) negative pressure compensation of the sluice or lock chamber and opening of the upper flap. It will be noted that the cycle of each sluice chamber is displaced, in phase, with respect to the cycle of adjacent sluice chambers.

An advantage of the sluice or lock described consists in that there are no frictionally stressed packings between the flaps, closing the individual chambers, and the chamber surfaces. These flaps tightly engage the packings, and there is no relative movement between the packings and the flaps when the latter are closed. Another advantage of the described apparatus is that, with the exception of the rotational drive for the entire drum 10, which requires a relatively small motor, there is no need for additional organs such as motors, pneumatic elements, program control devices, etc., to actuate the flaps. The actuation of the flaps is efiected simply by pressures existing in the overall system, such as negative pressures, atmospheric pressure and, possibly, superatmospheric pressures. The sluice or lock thus is distinguished by a very low cost for instrumentation on the one hand, and lower maintenance and operation expenses on the other. These advantages are of particular importance for the economical use of the described sluice or lock for abrasive products, products containing foreign bodies, products having dust particles, and products having high moisture contents.

FIG. 6 illustrates an embodiment of the invention which is generally similar to FIG. 1, but which is particularly applicable when the ratio of negative pressure in feed zone 22 to the ambient pressure surrounding drum 19 is very unfavorable. In such case, and as illustrated in FIG. 6, outer ends of cylinders 33 are simply extended to a -U-shaped ring 70 surrounding drum 10. Ring 70 opens upwardly and associated therewith is a second and fixed U-shaped ring 71 which opens downwardly and which has connected thereto a superatmospheric pressure line 72 connecting ring 71 to a compressor 75. As distinguished from the arrangement of FIGS. l-5, the pressure provided by compressor '75 is now operative on pistons 32, rather than atmospheric or ambient pressure, upon opening of flap valves 40. Thus, the flaps can still be closed even with very great pressure differentials. Aside from this, the operation of the embodiment shown in FIG. 6 is the same as that of the embodiment shown in FIGS. l-S, and the embodiment of FIG. 6 has the advantage that it is not necessary to ensure a minimum negative pressure.

FIGS. 7 and 8 illustrate an arrangement in which, without deviating from the basic principles of the invention, the large and relatively expensive step bearing losses between drum 1t} and fixed piece 7 can be avoided, and the sluice or lock device used for feeding either pressure pneumatic conveyors or steep pneumatic conveyors. In the embodiment shown in FIGS. 7 and 8, as contrasted to that shown in FIGS. 1-5 and 6, drum 101 is fixed and feed device 106 revolves, and has a conical bottom 80 formed with discharge apertures 27 with each of which there is associated a flap 29 and a packing or seal 62. A conical insert 81 subdivides the upper part of drum 100 into a feed zone 22 and a chamber zone 82 which, in turn, is subdivided by partitions 83 into individual sluice or lock chambers 20.

The driving means is arranged at the bottom of the apparatus, and comprises a motor 12, a pulley 85, a wheel 86 having spokes 87, and a belt 88 interconnecting pulley 85 and wheel 86. The spokes 87 of wheel 86 slope downwardly and inwardly from the wheel rim and have their inner ends secured to a drive shaft 90. Shaft 90 extends centrally upwardly through drum 180 into feed zone 22, and the revolving discharge mouth 107 is connected to the upper end of shaft 90. Discharge mouth 107, forming part of the feed device 1%, carries control cam 44 and cam plate St A stationary feed tube 192 extends coaxially into an axially extending part of discharge member 107. An exhaust air line 104 extends from feed zone 22 and may be connected, for example, with a dust separator which has not been shown.

In the embodiment shown in FIGS. 7 and 8, it is assumed that material is supplied from a separator, such as a cyclone, through the tube 1512 to the sluice or lock chambers. Conical partition 81 is formed with feed apertures 26, each having associated therewith a pivotal closure flap or door 28 and a packing or seal 34. Longitudinally arcuate piston rods 30 are connected with flaps 28 and secured to pistons 32 displaceable in longitudinally arcuate cylinders 33. These cylinders are extended upwardly rectilinearly and open into the space around drum 100. At the level of control cam 44, each cylinder 33 is provided with a respective control flap valve 413 each having operating crank 41 carrying roller 42 located in the path ,of control cam 44.

In angularly spaced relation with cylinders 33, there are provided tubes 99 extending from the interiors of chambers 20 into feed zone 22. Tubes 99 serve for pres- .sure compensation and, within feed zone 22, are provided with rotatable flap valves 94 having operating levers 95 carrying rolls 96 projecting into the path of cam plate 50.

As distinguished from the arrangement shown in FIGS. 1 through 6, lower closures 29 merely have counter weights 110 secured thereto. Below the discharge apertures 27, drum 1% is designed as a funnel 101, and the entire drum is subdivided into three chambers 20, for example. The spokes 87 of wheel 86, adjacent the lower part of drum 160, are so arranged that, during discharge of a chamber 20, they do not extend through the path of flow of the discharged material.

With the arrangement of FIGS. 7 and 8, and if it is assumed that feed device 106, together with control earn 104 and cam plate 50, rotates counterclockwise as viewed from the top or as shown by the arrow in FIG. 8, the following mode of operation results. First. all control valves 40 are closed. The rotary valve 94 in the tube 99 extending from chamber B into feed zone 22 is opened, while the corresponding rotary flaps 94 of chambers A and C are closed. Material flows into chamber A, this chamber being at the same pressure as feed zone 72 which, in the present example, is a negative pressure. Due to the negative pressure in chamber A, lower flap 29 is pressed firmly against packing 62 by the higher pressure prevailing outside of drum 100. During the filling process, feed device 106 continues to rotate counterclockwise. The upper flap 28 of chamber A remains opened as roller 42 on its lever 41 is engaged with control cam 44 and therefore maintains the control valve 40 in the associated cylinder 33 closed. Thus, this cylinder 33 is at the negative pressure prevailing in the feed zone 22 and in chamber A. During a certain part of the time required to fill chamber A, rotary valve 94 located between chamber B and feed zone 22 remains opened and pressure compensation is effected. This pressure compensation also is effective in cylinder 33 extending from chamber B, through the compensating bores 38, and since the respective control valve 40 is closed. The lower flap 29 of chamber B ha already been closed, after discharge has been completed, by means of its counter weight 110. With the increasing vacuum in chamber B, its lower flap 29 is pressed with increasing force against packing 62 by the normal external pressure. Thus, chamber B is prepared for filling.

During filling of chamber A, chamber C is discharged. Discharge occurs in the following manner. After filling of chamber C has been completed, roll 42 of lever 41 of the associated control valve 40 disengages control cam 44. Thus, the normal external atmospheric pressure or ambient pressure is operative on piston 32 to close the upper flap 28 and to clear, when closed, bores 38 in the associated cylinder 33 in order to effect pressure compensation of chamber C to the external pressure. This pressure compensation manifests itself in an intensified closing pressure on upper flap 28, due to the negative pressure prevailing in feed zone 22. This further maintains the negative pressure in feed zone 22. With the normal ambient pressure existing in chamber C, the weight of material in chamber C becomes fully operative against its lower flap 28 and pushes this lower flap 28 downwardly against the force of counter weight 110 so that chamber C is evacuated. As, during this evacuation, it is no longer necessary to keep control valve flap 40 of the respective cylinder 33 opened, control cam 44 re-closes this valve 40. However, and since aperture 27 is opened, the ambient pressure is operative on upper flap 28 maintaining the latter securely closed. When discharge from chamber C is completed, counter weight 110 re-closes lower flap 29 and thus prepares chamber C for pressure compensation at a negative pressure.

As will be noted from FIG. 8, such pressure compensation is now taking place at chamber B. The pressure com pensation between chamber B and feed. zone 22 now effects, on the one hand, an increasing pressure of lower flap 29 on packing 62 around discharge aperture 27, due to the differential between the ambient outside pressure and the negative inside pressure, and, on the other hand, at the moment of an approximate pressure equilibrium between chamber B and feed zone 22, an opening of upper flap 28 by the dead weight of the latter inasmuch as the ambient external pressure is throttled by control valve 40. At this time, chamber B is ready to receive material.

In contrast to the arrangement shown in FIGS. 1-6, the' embodiment of the invention shown in FIGS. 7 and 8 has the advantage that it is no longer necessary to rotate the entire drum together with all of the material to be sluiced. In arrangement of FIGS. 7 and 8, only the feed device 107, together with cam plate 50 and control cam 44, is rotated. This results in simplification of the support of rotating parts so that, especially in the case of expensive bearing elements and their installation, savings can be achieved. Other than this, the principle of operation of the apparatus remains unchanged.

FIG. 9 illustrates an embodiment of the invention which may be used for transferring material from a suction pneumatic conveyor into a pressure pneumatic conveyor. A the arrangement of FIG. 9 involves no change in the principle of operation, and generally is similar to that of FIGS. 7 and 8, the following description is limited to certain differences between the arrangement of FIG. 9 and that of FIGS. 7 and 8.

As one of these differences, it is not necessary that the compensation apparatus be provided with separate compensating means in partition 81 between chambers 20 and feed zone 22. Instead, valves 115 may be provided in upper flaps 28. If now the longitudinally arcuate cylinders 33 are mounted in covers 45, there is the advantage that the entire flap system and its control can be installed and disassembled as a unit. A pressure line 119, provided with a throttle valve 118, extend from pressure pneumatic conveyor 117 to the individual control valves 40. Spoke wheel 86, provided for driving feed device 106, is de signed to form a control track 120 engaged by substantially spherical counter weights 111 of lower flaps 29.

For the special purpose of protecting axially spaced bearings 121 and 122 of central drive shaft 90 against wear and abrasion, the zone 123 between these bearings, which surrounds drive shaft 90, is designed as a pressure zone which communicates with pressure line 119 and therefore has a positive pressure. Thereby, no abrasive dust and the like can penetrate into the shaft packings and bearings 121 and 122 of shaft 90. In the same manner as in the embodiment of FIGS. 7 and 8, feed device 106 carries cam plate '50 and control cam 44 for valves 15. 1 An exhaust air line 104 connects the feed zone to the material supply line of cyclone separator 113. Thus, dusts from feed zone 22 are' returned into the cyclone 113 and thence are conducted away. In the embodiment of FIG. 9, the feed device is designed as a so-called dead beater. That is, the material to be sluiced first falls onto the horizontal bottom plate 127 where its kinetic energy is dissipated. Subsequently, the material flows from discharge aperture 126 into feed apertures 26. The rhythrn of the material sluicing is the same, that is, filling, closing, pressure compensation, evacuation, pressure compensation, and the" cycle repeats.

The embodiment of FIG. 9 differs from those previously described in that control of lower flaps 29 is effected by control track 120 through the substantially spherical counter weights 111. Furthermore, the entire system is closed against ambient or atmospheric pressure, the already existing pressure conditions are utilized for the conveyance of material and for the control of operat1on of the apparatus, these pressures being the existing negative pressure and the existing superatmospheric pressure of the respective conveyors. As compared with known systems for sluicing material between transport systems at different pressures, the embodiment of FIG. 9 has the advantage that, despite very large sluicing outputs, there is a Illlnlmum amount of air infiltration. The arrangement is very insensitive to abrasives, moist materials, differences in granulations, and the proportion of dust.

FIG. 10 illustrates an embodiment of the invention providing for sluicing of material into a pressure pneumatic conveyor, wherein the material passes from a zone at normal atmospheric pressure into a super-atmospheric pressure zone. Inside or above feed zone 22, wherein feed device 106 rotates, there is a feed funnel 10% opening into feed device 106. Feed device 106 carries drive wheel 130 which is connected through belt 88 with pulley 85 of motor 12, and also carries control cam 44 and cam plate 50. Control cam 44 serves to actuate individual control switches 132, each of which is connected with a voltage source and with a servo motor 134, illustrated as a draw or traction solenoid.

The individual flaps associated with the respective feed apertures 26 are connected through rods 30 to pistons 32 which are displaceable in straight or rectilinear cylinders 13-3. These cylinders have compensating bores 38 and are provided with control flaps 40, in the same rnanner as previously described. Pressure compensating valves 48, which are biased to the closed position by springs 47, are arranged adjacent the upper edge of conical insert 81 disposed between sluice chambers 20 and feed zone 22. Each crank 41 of a control flap 40 is articulatedly connected with the armature 136 of a solenoid 134. Below the evacuating or discharge apertures 27, provided with respective lower flaps 29 having counter weights 110, a funnel 101 is provided as an extension of drum 100 and leads to the pressure pneumatic conveyor 117. A pressure line 119 extends between pressure pneumatic tube 117 and the individual cylinders 133, and is provided with a throttle valve 118.

In contrast to the mechanical actuation of control flaps 40 characteristic of the embodiments of FIGS. 1-9, the control flaps 40 of FIG. 10 are actuated by the electromagnetic elements 134 which are under the influence of control cam 44 acting on control switches 132. Furthermore, in contrast to the previously described embodiments having stationary drums, the drive is here provided at the upper end. This offers the advantage that the material to be sluiced can no longer come in contact with the drive wheels, such as the wheel 130, and that shaft packings are superfluous. Thus, the drive system is somewhat more compact. However, the fundamental mode of operation has not been changed in the embodiment of FIG. 9, but this embodiment has an advantage that sluicing the material from a zone at an ambient or atmospheric pressure into a zone at superatmospheric pressure is possible.

The embodiment of the invention shown in FIG. 11 corresponds, in principle, to a section XIXI of FIG. 8 and has, as a characteristic feature, pneumatic actuation of lower flaps 29. The basic consideration in the embodiment of FIG. 11 is that control and actuation of the flaps is possible not only for the upper flaps, but also for the lower flaps, utilizing the existing pressure conditions within the sluice and outside thereof. The sluice serves to transfer material between a suction pneumatic conveyor 1 and a pressure pneumatic conveyor 117. After passing through a cyclone separator 113, the material flows into feed device 106 and thence, in succession, into the several chambers 20 from which the material is transferred to the pressure pneumatic conveyor 117. Lower flaps 29, which are pivotally connected to conical bottom 80 of chambers 20 through brackets 61 are connected to piston rods and pistons 142, the latter being displaceable in longitudinally arcuate cylinders 143. When flaps 29 are closed, pistons 142 clear bores 148 to establish communication between cylinders 143 and zones 145 surrounding the cylinders and connected by lines to feed zone 22. Within feed zone 22, lines 150 are closable by rotary valves 94 provided with levers 95 having rollers 96 engageable with cam plate 5%. The air pressure prevailing in pressure pneumatic conveyor 117 is supplied through line 119, provided with throttle valve 118, to the individual cylinders 33 having respective control valves 40 and respective pistons 32 each associated with a respective upper flap 28.

While the filling of the individual sluice or lock chambers 20, and the actuation of upper flaps 28, in the embodiment of FIG. 11 is the same as in the embodiments previously described, there is a difference in the evacuation of the sluice or lock chambers and the pressure compensation between feed zone 22 and the respective chambers 20. During the filling of one sluice chamber 20, its upper flap 28 is opened and, at the same time, the control valve 40 of the associated cylinder 33 is closed. Also, the

associated lower fiap 29 is closed and, both in feed zone 22 and in the respective sluice or lock chamber 20, there is a negative pressure. Thereby, the pressure difference, between the negative pressure within the respective sluice chamber 20 adjacent funnel 101 and the pressure within the pressure pneumatic conveyor 117, pushes the respective lower flap 29 to the closed position. The rotary valve 94 in the line 150 connecting the respective cylinder 143 into feed zone 22 is opened. As piston 142 of the respective lower flap 29 is at the inner end of cylinder 143, pressure compensation between sluice chamber 20 and feed zone 22 is effected through cylinder 143 and the bores 148 therein, and further through tube 150.

When filling of the respective sluice chamber 20 is completed, its associated control valve 40 is opened, as usual, and the superatmospheric pressure of pressure pneumatic conveyor 117 becomes effective on the associted piston 32. The latter thus closes the associated upper flap 28 and, with this flap closed, the superatmospheric pressure is effective within sluice chamber 20. At the same time, rotary flap valve 94 is closed so that, by virtue of the superatmospheric pressure and the material weight Within the respective chamber 20, its lower flap 29 is opened and the material in the chamber is discharged into the pressure pneumatic conveyor 117. For closing the lower flap, rotary flap valve 94, at the top of the apparatus, is opened through cam 51 and the roller 96 is associated with the flap 94. The superatmospheric pressure of conveyor 117 acts, at first, on the surface of piston 142 facing toward lower fiap 29 and thus pushes this flap 29 to the closed position. Further and firmer closing is effected by the pressure differential on lower fla 29, which, with increasing vacuum effected through line 150 and bores 148 of the respective sluice chambers 20, is increased. At the approximate pressure equilibrium. between feed zone 22 and the respective sluice chamber 20, the respective upper flap 28 opens and the cycle is repeated.

The embodiment of the apparatus shown in FIG. 11 may be used, with advantage, where materials are to be sluiced between the zones of different pressures and with these pressures being different from the ambient or atmospheric pressure. A further advantage is that the entire pneumatic control and actuating system is selfenclosed, so that malfunctioning due to dust is substantially avoided.

In the arrangement shown in FIG. 12, a stationary chamber sluice 170, having a construction similar to that of the embodiments of FIGS. 7-11, and an upper cyclone chamber 113 are provided. A dust air line 14 nearer to dust separator 151, is connected by a longitudinally arcuate piston rod 156 with a piston 158 displaceable in a longitudinally arcuate cylinder 157. Cylinder 157 is connected through a line 159 with the cylinder 33 operating an upper flap of sluice or look device 170. A second line 169 connects sluice section 153 to that chamber 20 of device 170 whose cylinder 33 is connected to line 159. Each line 159 and 168 has a check valve, 162 and 167, respectively, therein. In line 159, check valve 162 acts against the air current in cylinder 33 and, in line 169, check valve 167 acts against the air current in sluice 153. A second, counter weight-loaded flap valve 165 spaced from flap 155 delirnits sluice 153. The apparatus as thus far described results in the following mode of operation, and in which the numbers in parentheses refer to FIGS. 1-11.

In feed zone (22) of the device 7, and in the zone of dust separator 151, there exists approximately the same negative pressure conditions. During the filling of a chamber (20) in device 170, the chamber likewise has a negative pressure therein. Through check valve 168, which prevents How of dust and material into sluice section 153, this negative pressure is present in sluice section 153. Sluice section 153 is thus opened by the dead weight of flap 155, so that the dust can flow from dust separator 151 into sluice section 153. The counter weight and the normal ambient or atmospheric pressure push the second flap valve 165 to the closed position.

After filling of the respective chamber (20) is completed, the control valve (40) in its cylinder 33 is opened, and the ambient or atmospheric pressure closes the upper flap (28) and, at the same time, through line 159 and check valve 162, and through the medium of piston158 and piston rod 156, closes the flap 155. When flap is closed, this ambient or atmospheric pressure prevails in sluice section 153 through line 154 connected to cylinder 157, and becomes effective also in sluice section 153. This normal pressure, together with the dust load, opens lower flap and thus transfers the dust into collecting tank 161). Because of the check valve 167 in line 169, the ambient or atmospheric pressure cannot become operative in the respective chamber (211). As soon as this chamber (20) has its pressure compensated to the negative pressure prevailing in feed zone (22), a similar compensation occurs in sluice 153 so that a new cycle is initiated. As sluicing out of the dust need not take place too often, it is sufiicient to connect a pneumatically actuated flap valve 155 of sluice 153 to only one of the control cylinders (33) of device 171) so that dust discharge will occur once during each revolution of feed device (106).

The apparatus shown in FIG. 12 has the advantage that no additional control and actuating means for sluice 153 are needed below dust separator 151. Control of auxiliary sluice 153 occurs from the actual material sluice or lock 17 0. It is within the scope of the invention to operate lower flap 165 of sluice 153 pneumatically in the same manner, but in phase displaced relation to upper flap 155.

The mode of operation and the outstanding novel features of the invention have been shown and described with reference to a few typical construction examples. The chamber sluice or lock of the invention is characterized by substantially complete independence with respect to the product conveyed, granulation, dust proportion, and moisture. It is substantially insensitive to variations in the product, especially since there are no relative movements of packing parts and because the operating pistons are always operated with clean fresh air. However, and without departing from the underlying concept of the invention, numerous variations in construction are possible.

For example, other designs of the pneumatic actuating pistons for the lower flaps may be used. Furthermore, in the region of the feed Zone variations in the partition are possible to improve the fluidity of the materials, particularly to prevent formation of harmful material deposits which can be removed only with difliculty, but these have not been illustrated in order to maintain the clarity and simplicity of the description and illustration of the invention. It will be clear that the construction of the sluice or lock is not limited to three chambers or four chambers, as shown, but that any other number of chambers, may be used. It is even possible to use only two chambers. With respect to the control flap and pressure compensation valve operations, it should be pointed out that any servo system may be used for actuating these elements, whether it is an electro-mechanical system, an electropneumatic system, an electro-hydraulic system, a hydraulic-mechanical system, or any combination of these. Solely for reasons of simplifying the disclosure, the latter has been limited to an illustration of a mechanical and an electro-mechanical operating system. Furthermore, while a particular belt drive has been illustrated, it will be appreciated that it is immaterial whether this drive is at the lll top or at the bottom, or whether or not it is substituted by motors and transmission gearing disposed centrally of the housing. If the foregoing description, straight or funnel-shaped upper and lower ends of the chambers have been shown and described and, while these are advantageous, other designs of the ends of the chambers may be used. Thus, it is easily possible to reduce the proportion of dead spaces by forming chamber zones with the proper configuration.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; and a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective closures in accordance with the relative rotation of said drum and said feed device and in accordance with the relative angular relation between the respective sluice chamber and said feed device.

2. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a

drum, having a substantially upright axis, operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; and a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective closures in accordance with the relative rotation of said drum and said feed device and in accordance with the relative angular relation between the respective sluice chamber and said feed device.

3. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; and .a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective closures in accordance with the relative rotation of said drum and said feed device and in accordance with the relative angular relation between the respective sluice chamber and said feed device; said closures comprising swingably mounted flaps, and said operating means comprising fluid pressure actuators.

4. Apparatus for the transfer of bulk material between zones at diflerent respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum operatively associate-d with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; and a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective closures in accordance with the relative rotation of said drum and said feed device and in accordance with the relative angular rotation between the respective sluice chamber and said feed device; said closures comprising flaps swingably mounted for movement toward and away from the associated apertures; said operating means comprising pistons each connected to the respective flap by a longitudinally arcuate piston rod, each piston operating in a longitudinally arcuate cylinder in it which is subjected to fluid pressure.

5. Apparatus for the transfer of bulk material between zones at different respective fluid pressures; said apparatus comprising, in combination, a material feed device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; said closures comprising flaps mounted for swinging movement toward and away from the associated aperture; and a plurality of fluid pressure actuators, each including a piston connected to a respective flap and operating in a respective cylinder; said fluid pressure actuators cyclically opening and closing the respective flaps in accordance with such relative rotation of said drum and said feed device and in accordance with the relative angular position of the associated sluice chamber relative to said feed device; each cylinder projecting outwardly from the associated sluice chamber and each piston being subjected to fluid pressure.

6. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; said closures comprising flaps mounted for swinging movement toward and away from the associated aperture; and a plurality ofvfiuid pressure actuators, each including a piston connected to a respective flap and operating in a respective cylinder; said fluid pressure actuators cyclically opening and closing the respective flaps in accordance with such relative rotation of said drum and said feed device and in accordance with the relative angular position of the associated sluice chamber relative to I said feed device; each cylinder projecting outwardly from the associated sluice chamber and each piston being subjected to fluid pressure; each piston being connected to its associated flap by a longitudinally arcuate piston rod substantially concentric with its swinging axis; each cylinder being longitudinally arcuate about the swinging center of its associated flap.

7. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; said closures comprising flaps mounted for swinging movement toward and away from the associated apertures; a plurality of fluid pressure actuators, each including a piston connected to a respective flap and operating in a respective cylinder; said fluid pressure actuators cyclically opening and closing the respective flaps in accordance with such relative rotation of said drum and said feed device and in accordance with the relative angular position of the associated sluice chamber relative to said feed device; each cylinder projecting outwardly from the associated sluice chamber and each piston being subjected to fluid pressure; each cylinder having an inner end i opening into the associated sluice chamber, and an open outer end; and valve means selectively operable to close I the outer end of each cylinder.

8. Apparatus for the transfer of bulk material between zones at different respective fluid pressures; said apparatus :of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; said closures comprising flaps mounted for swinging movement toward and away from the associated aperture; and a plurality of fluid pressure actuators, each including a piston connected to a respective flap and operating in a respective cylinder; said fluid pressure actuators cyclically opening and closing the respective flaps in accordance with such relative rotation of said drum and said feed device and in accordance with the relative angular position of the associated sluice chamber relative to said feed device; each cylinder pro- ,jecting outwardly from the associated sluice chamber and each piston being subjected to fluid pressure; each cylinder having apertures in a cylindrical surface adjacent its open inner end and effective to establish com- 1 munication' between the interior of the associated cylinder and the associated sluice chamber; each piston, at its limit of inward movement in its associated cylinder, clearing said apertures to connect the associated sluice chamber to the interior of the associated cylinder outwardly of the associated piston.

9. Apparatus for the transfer of bulk material between zones at diflerent respective fluid pressures, said apparatus comprising, in combination, a material feed device; a

drum operatively associated with said device; means sub dividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated apertures therein; said closures comprising flaps mounted for swinging movement toward and away from the associated aperture; a plurality of fluid pressure actuators, each including a piston connected to a respective flap and operating in a respective cylinder; said fluid pressure actuators cyclically opening and closing the respective flaps in accordance with such relative rotation of said'drum and said feed device and in accordance with the relative angular position of the associated sluice chamber relative to said feed device; each cylinder projecting outwardly from the associated sluice chamber and each piston being subjected to fluid pressure; each cylinder having an inner end opening into the associated sluice chamber, and an open outer end; each cylinder being formed, adjacent its open inner end, with apertures and in a cylindrical surface adapted to establish communication between the asso ciated sluice chamber and the interior of the respective cylinder; each piston, in its innermost position, clearing the apertures in the associated cylinder to establish communication between the associated sluice chamber and the interior of the associated cylinder outwardly of the respective piston; flap valves selectively operable to close the open outer ends of said cylinders, each flap valve being associated with a respective cylinder; flap valve operating means each operatively connected to a respective flap valve; and control means for said flap valve operating means each stationary, relative to its associated flap valve operating means, with respect to angular displacement relative to the axis of said drum; said control means cyclically operating the associated flap valve operating means in accordance with such relative rotation of said drum and said device and in accordance with the relative angular relation of the associated sluice chamber with respect to said feed device.

10. Apparatus for the transfervof bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material 'feed device; a drum operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relation rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective as sociated aperture therein; said closures comprising flaps mounted for swinging movement toward and away from the associated aperture; a plurality of fluid pressure actuators, each including a piston connected to a respective flap and operating in a respective cylinder; said fluid pressure actuators cyclically opening and closing the respective flaps in accordance with such relative rotation of said drum and said feed device and in accordance with the relative angular position of the associated sluice chamber relative to said feed device; each cylinder projecting outwardly from the associated sluice chamber and each piston being subjected to fluid pressure; each cylinder having an inner end opening into the associated sluice chamber, and an open outer end; each cylinder being formed, adjacent its open inner end, with apertures in a cylindrical surface adapted to establish communication between the associated sluice chamber and the interior of the respective cylinder; each piston, in its innermost position, clearing the apertures in the associated cylinder to establish communication between the associated sluice chamber and the interior of the associated cylinder outwardly of the respective piston; flap valves :ating means each operatively connected to a respective flap valve; and control means for said flap valve opera-ting means each stationary, relative to its associated flap valve operating means, with respect to angular displacement relative to the axis of said drum; said control means cyclically opera-ting the associated flap valve operating means in accordance with such relative rotation of said I drum and said device and in accordance with the relative angular relation of the associated sluice chamber with respect to said feed device.

11. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; said closures comprising flaps mounted .for swinging movement toward and away from the associated aperture; a plurality of fluid pressure actuators, each including a piston connected to a respective flap and operating in a respective cylinder; said fluid pressure actuators cyclically opening and closing the respective flaps in accordance with such relative rotation of said drum and said feed device and in accordance with the relative angular position of the .associated sluice chamber relative to said feed device; each cylinder projecting outwardly from the associated sluice chamber and each piston being subjected to fluid pressure; each cylinder having an inner end opening into the associated sluice chamber, and an open outer end; valve means selectively operable to close. the outer end of each cylinder; and

means connecting the open outer ends .of said cylinders to a zone at a positive pressure.

12. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed I region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and .away from the chamber surface having the respective associated aperture therein; said closures comprising flaps mounted for swinging movement toward and away from the associated aperture; a plurality of fluid pressure actuators, :each including a :piston connected to a respective flap and operating in a respective cylinder; said fluid pressure actuators cyclically opening and closing the respective flaps in accordance with such relative rotation of said drum and said feed device and in accordance with the relative angular position of the associated sluice chamber relative to said feed device; each cylinder projecting outwardly from the associated sluice chamber and each piston being subjected to fluid pressure; each cylinder having an inner end opening into the associated sluice chamber, and an open outer end; valve means selectively operable to close the outer end of each cylinder; an annular conduit substantially coaxial with said drum and substantially stationary with respect to said cylinders, the interior of said annular conduit being at a positive pressure;

i6 and means connecting the open outer ends of said cylinders to said annular conduit.

13. Apparatus for the transfer of bulk material, as claimed in claim 1, in which said feed device is stationary and said drum is mounted for rotation.

14. Apparatus for the transfer of bulk material, as claimed in claim 1, in which said feed device is mounted for revolution about the axis of said drum, and said drum is stationary.

15. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum, having a substantially upright axis, operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective closures in accordance with the relative rotation of said drum and said feed device and in accordance with relative angular relation between the respective sluice chamber and said feed device; said discharge apertures being at the lower end of said drum; driving means adjacent said discharge apertures; means forming a tubular passage extending substantially coaxially of said drum; a driving shaft extending through said tubular passage and connecting said driving means to said feed device; a pair of bearing means for said shaft mounted in said tubular passage, one adjacent said filling apertures and the other adjacent said discharge apertures; and means for applying a positive fluid pressure to said tubular passage between said bearing means.

16. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum, having a substantially upright axis, operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective angular relation between the respective sluice chamber and said feed device; said feed zone being funnel-shaped and open at the top; a feed funnel, open at the top, operable to feed the material to said feed device; and a pneumatic conveyor arranged to receive material from said discharge apertures and positioned adjacent the latter.

17. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum, having a substantially upright axis, operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated With a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective closures in accordance with the relative rotation of said drum and said feed device and in accordance with relative angular relation between the respective sluice chamber and said feed device; pressure compensation apertures establishing communication between each of said sluice chambers and said feed zones; and closure means each associated with a respective pressure compensation aperture.

18. Apparatus for the transfer of bulk material between zones at dilferent respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum, having a substantially upright axis, operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means efli'ecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective closures in accordance with the relative rotation of said drum and said feed device and in accordance with relative angular relation between the respective sluice chamber and said feed device; pressure compensation apertures establishing communication between each of said sluice chambers and said feed zones;

closure means each associated with a respective pressure compensation aperture; and means for operating said closure means synchronously with respect to the opening and closing movements of said closures for said filling and discharge apertures.

19. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum, having a substantially upright axis, operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective closures in accordance with the relative rotation of said drum and said feed device and in accordance with relative angular relation between the respective sluice chamber and said feed device; pressure compensation apertures establishing communication between each of said sluice chambers and said feed zones; closure means associated with a respective pressure compensation aperture; means for operating said closure means synchronously With respect to the opening and closing movements of said closures for said filling and discharge apertures; fluid pressure operated piston-cylin der actuators, each including a piston connected to a respective closure for a discharge aperture and operating in a respective cylinder; and means connecting each cylinder to said feed zone through a respective compensating aperture.

20. Apparatus for the transfer of bulk material between zones at dilferent respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum operatively associated with said device;

means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective closures in accordance with the relative rotation of said drum and said feed device and in accordance with relative angular relation between the respective sluice chamber and said feed device; and counter weights each connected to a closure for a discharge aperture, the closures for the discharge apertures being conjointly operable by said counter weights and by negative pressure in the region of said discharge apertures.

21. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; and a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective closures in accordance with the relative rotation of said drum and said feed device and in accordance with relative angular relation between the respective sluice chamber and said feed device; the operating means for the closures for the discharge apertures comprising levers each connected to a respective discharge aperture closure, and cam means cooperable with said levers.

22. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; means effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed device to define a feed zone; means mounting said closures for movement bodily toward and away from the chamber surface having the respective associated aperture therein; a plurality of operating means, each individual to a respective closure, said operating means cyclically opening and closing the respective closures in accordance with the relative rotation of said drum and said feed device and in accordance with relative angular relation between the respective sluice chamber and said feed device; a pneumatic conveyor feeding material to said apparatus; and a material separator connected to the discharge of said pneumatic conveyor and opening into said feed zone.

23. Apparatus for the transfer of bulk material between zones at different respective fluid pressures, said apparatus comprising, in combination, a material feed device; a drum operatively associated with said device; means subdividing said drum into individual sluice chambers each having respective filling and discharge apertures; a plurality of closures, each associated with a respective one of said apertures; -rneans effecting relative rotation of said drum and said feed device; said drum extending axially beyond said sluice chambers into the region of said feed 

1. APPARATUS FOR THE TRANSFER OF BULK MATERIAL BETWEEN ZONES AT DIFFERENT RESPECTIVE FLUID PRESSURES, SAID APPARATUS COMPRISING, IN COMBINATION, A MATERIAL FEED DEVICE; A DRUM OPERATIVELY ASSOCIATED WITH SAID DEVICE; MEANS SUBDIVIDING SAID DRUM INTO INDIVIDUAL SLUICE CHAMBERS EACH HAVING RESPECTIVE FILLING AND DISCHARGE APERTURES; A PLURALITY OF CLOSURES, EACH ASSOCIATED WITH A RESPECTIVE ONE OF SAID APERTURES; MEANS EFFECTING RELATIVE ROTATION OF SAID DRUM AND SAID FEED DEVICE; SAID DRUM EXTENDING AXIALLY BEYOND SAID SLUICE CHAMBERS INTO THE REGION OF SAID FEED DEVICE TO DEFINE A FEED ZONE; MEANS MOUNTING SAID CLOSURES FOR MOVEMENT BODILY TOWARD AND AWAY FROM THE CHAMBER SURFACE HAVING THE RESPECTIVE ASSOCIATED APERTURE THEREIN; AND A PLURALITY OF OPERATING MEANS, EACH INDIVID- 